Polyaxial pivot housing for external fixation system

ABSTRACT

A polyaxial pivot housing for an external fixation system, comprising a first plate; a second plate substantially parallel to the first plate; a spherical member positioned between the first and second plates, the spherical member having a threaded post that is configured to attach to a support member of an external fixation frame; and a pivotably rotatable locking arm, the locking arm being configured to orientationally lock the threaded post with respect to the external fixation frame by compressing the first and second plates against the spherical member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to and claims priority to U.S. ProvisionalPatent Application Ser. Nos. 61/789,429 and 61/788,414, each of whichwere filed on Mar. 15, 2013, the complete and entire disclosures ofwhich are hereby expressly incorporated by reference herein.

TECHNICAL FIELD

The present teachings are related to an orthopedic external fixationsystem, and more particularly to an external fixation system havinguniversal articulation units for positioning fixation components,including rings, pins, rods, bars and posts relative to a patient'sanatomy.

BACKGROUND OF THE DISCLOSURE

The statements in this section merely provide background informationrelated to the present disclosure and should not be construed asconstituting prior art.

In various orthopedic surgical procedures, it is often necessary tosecure or stabilize two or more portions of bone or soft tissue relativeto one another. This need is often the result of a bone or soft tissueinjury, such as an acute fracture of the bone. To ensure that thedamaged bone fragments are capable of properly regenerating, it isimportant that the bone fragments be adequately stabilized during theregeneration process. To adequately stabilize the injured bone fragmentsand/or soft tissue, a bone distraction frame is typically installed ontothe patient.

Once a distraction frame has been installed onto a patient, it issometimes necessary to further adjust the frame to fine tune thealignment of the damaged bone fragments or soft tissue. This process,which is referred to as “fracture reduction,” is typically performedunder the guidance of a C-arm (X-ray) and involves the surgeon manuallypulling on the transfixation pin until the bones are aligned in adesired orientation. Once the surgeon is satisfied with this alignment,the clamps of the distraction frame can then be tightened.

While many external fixation devices have proven generally effective forstabilizing bones, these conventional systems are often difficult andtime consuming to adjust once assembled, particularly as the surgeon mayneed to manually loosen and retighten the clamps several times duringthe fracture reduction process. Not only is the adjustment process timeconsuming, but the health and safety of the surgeon is also potentiallycompromised, particularly as the surgeon must expose his hands to theX-ray field during the reduction process. Thus, it would be useful tohave an external fixation framing system that is not only easy toassemble, but also provides the surgeon with a greater degree offlexibility in terms of safely adjusting the frame once it has beenassembled.

The present application is intended to improve upon and resolve some ofthese known deficiencies of the art.

SUMMARY OF THE DISCLOSURE

According to a first aspect of the present teachings, a polyaxial pivothousing for an external fixation system is provided and comprises afirst plate; a second plate substantially parallel to the first plate; aspherical member positioned between the first and second plates, thespherical member having a threaded post that is configured to attach toa support member of an external fixation frame; and a pivotablyrotatable locking arm, the locking arm being configured toorientationally lock the threaded post with respect to the externalfixation frame by compressing the first and second plates against thespherical member.

According to another aspect of the present teachings, a polyaxial pivothousing for an external fixation system is provided and comprises afirst plate; a second plate substantially parallel to the first plate; alocking screw connecting the first and second plates; a spherical memberpositioned between the first and second plates, the spherical memberhaving a threaded post that is configured to attach to a support memberof an external fixation frame; and a pivotably rotatable locking arm,the locking arm being configured to orientationally lock the threadedpost with respect to the external fixation frame by compressing thefirst and second plates against the spherical member; wherein thepolyaxial pivot housing has a provisional locking feature and adefinitive locking feature, each locking feature being manuallyactuatable without the use of a tool.

Other objects and benefits of the disclosure will become apparent fromthe following written description along with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned aspects of the present disclosure and the manner ofobtaining them will become more apparent and the disclosure itself willbe better understood by reference to the following description of theembodiments of the disclosure taken in conjunction with the accompanyingdrawings, wherein:

FIG. 1A is a perspective view of an ankle spanning external fixationsystem in accordance with the teachings of the present disclosure;

FIG. 1B is a perspective view of a mid-shaft tibia spanning externalfixation system in accordance with the teachings of the presentdisclosure;

FIG. 1C is a perspective view of a knee-spanning external fixationsystem in accordance with the teachings of the present disclosure;

FIG. 2A is a perspective view of an illustrative external fixationclamping assembly having its locking arm in the open position inaccordance with the teachings of the present disclosure;

FIG. 2B is a perspective view of the illustrative external fixationclamping assembly of FIG. 2A having the locking arm in the closedposition;

FIG. 3A is a perspective view of another illustrative external fixationclamping assembly having its locking arm in the open position and havinga pair of upwardly projecting locking tabs that are configured to securethe locking arm in place in accordance with the teachings of the presentdisclosure;

FIG. 3B is a perspective view of the illustrative external fixationclamping assembly of FIG. 3A having the locking arm in the closedposition;

FIG. 3C is an inverted perspective view of the illustrative externalfixation clamping assembly of FIG. 3A showing a serrated surface forrotationally locking a stack of clamping assemblies relative to oneanother;

FIG. 4A is a perspective view of the illustrative external fixationclamping assembly of FIG. 3A shown clamped to a ring frame in accordancewith the teachings of the present disclosure;

FIG. 4B is a top view of the illustrative external fixation clampingassembly and ring frame of FIG. 4A;

FIG. 4C is a side view of the illustrative external fixation clampingassembly and ring frame of FIG. 4A;

FIG. 5A is a perspective view on an illustrative external fixationdistraction handle assembly in accordance with the teachings of thepresent disclosure;

FIG. 5B is a front view of the illustrative external fixationdistraction handle assembly of FIG. 5A;

FIG. 5C is a top view of the illustrative external fixation distractionhandle assembly of FIG. 5A;

FIG. 5D is a side view of the illustrative external fixation distractionhandle assembly of FIG. 5A;

FIG. 6A is a perspective view of an illustrative external fixationdistraction handle assembly extension arm in accordance with theteachings of the present disclosure;

FIG. 6B is a side view of the illustrative external fixation distractionhandle assembly extension arm of FIG. 6A;

FIG. 7A is a perspective view of an external fixation polyaxial pivothousing in accordance with the teachings of the present disclosure;

FIG. 7B is another perspective view of the external fixation polyaxialpivot housing of FIG. 7A;

FIG. 7C is a side view of the external fixation polyaxial pivot housingof FIG. 7A;

FIG. 7D is another side view of the external fixation polyaxial pivothousing of FIG. 7A;

FIG. 7E is another perspective view of the external fixation polyaxialpivot housing of FIG. 7A;

FIG. 7F is an exploded perspective view of the external fixationpolyaxial pivot housing of FIG. 7A;

FIGS. 7G-7H are the respective top and bottom housing rings of thepolyaxial pivot housing FIG. 7A;

FIG. 8 is an external fixation polyaxial pivot housing locking pin inaccordance with the teachings of the present disclosure;

FIG. 9A is a perspective view of a pair of external fixation polyaxialpivot housings and clamping assemblies connected to a ratcheting strutin accordance with the teachings of the present disclosure; and

FIG. 9B is a side view of the pair of external fixation polyaxial pivothousings and clamping assemblies connected to the ratcheting strut ofFIG. 9A.

FIG. 10 is a perspective view of another external fixation polyaxialpivot housing in accordance with the teachings of the presentdisclosure;

FIG. 11 is a perspective view of the external fixation polyaxial pivothousing of FIG. 10 shown associated with an illustrative externalfixation clamping assembly;

FIG. 12 is an exploded view of the external fixation polyaxial pivothousing and associated clamping assembly of FIG. 11;

FIG. 13 is a side view of the external fixation polyaxial pivot housingand clamping assembly of FIG. 11;

FIG. 14 is a bottom view of the external fixation polyaxial pivothousing and clamping assembly of FIG. 11;

FIG. 15 is an exploded perspective view of yet another embodiment of anexternal fixation polyaxial pivot housing in accordance with theteachings of the present disclosure;

FIG. 16A is a perspective view of still another embodiment of anexternal fixation polyaxial pivot housing in accordance with theteachings of the present disclosure;

FIG. 16B is a side view of the external fixation polyaxial pivot housingof FIG. 16A;

FIG. 16C is another side view of the external fixation polyaxial pivothousing of FIG. 16A;

FIG. 16D is an exploded perspective view of the external fixationpolyaxial pivot housing of FIG. 16A and associated with a clampingassembly in accordance with the teachings of the present disclosure;

FIG. 17A is a perspective view of an external fixation polyaxial pivothousing in accordance with one illustrative embodiment of the presentteachings and having internal locking rings shown in phantom;

FIG. 17B is an exploded perspective view of the external fixationpolyaxial pivot housing of FIG. 17A;

FIG. 17C is another exploded perspective view of an external fixationpolyaxial pivot housing in accordance with the present teachings;

FIG. 18 is a cross-sectional view of an external fixation polyaxialpivot housing in accordance with another illustrative embodiment of thepresent teachings and having a wave spring locking assembly;

FIG. 19A is an exploded perspective view of another external fixationpolyaxial pivot housing having a series of mating protrusions forpreventing rotation in accordance with the present teachings;

FIG. 19B is another exploded perspective view of the external fixationpolyaxial pivot housing of FIG. 19A;

FIG. 20 is an illustrative external fixation stacked rod/pin clampingassembly in accordance with the teachings of the present disclosure;

FIG. 21 is an illustrative cam nut locking assembly in accordance withthe teachings of the present disclosure;

FIG. 22 is an illustrative frame to rod/pin external fixation clampingassembly in accordance with the teachings of the present disclosure;

FIG. 23 is an illustrative cam nut locking assembly in accordance withthe teachings of the present disclosure;

FIG. 24 is an illustrative ring-to-post external fixation clampingassembly in accordance with the teachings of the present disclosure;

FIG. 25 is another illustrative rod/pin clamp external fixation clampingassembly in accordance with the teachings of the present disclosure;

FIG. 26 is another illustrative rod/pin external fixation clampingassembly in accordance with the teachings of the present disclosure;

FIGS. 27 and 28 depict an illustrative ring frame to rod/pin externalfixation clamping assembly in accordance with the teachings of thepresent disclosure; and

FIG. 29 is another illustrative ring-to-post clamping assembly inaccordance with the teachings of the present disclosure.

DETAILED DESCRIPTION

The above-mentioned aspects of the present application and the manner ofobtaining them will become more apparent and the teachings of thepresent application itself will be better understood by reference to thefollowing description of the embodiments of the present applicationtaken in conjunction with the accompanying drawings.

The embodiments of the present application described below are notintended to be exhaustive or to limit the teachings of the presentapplication to the precise forms disclosed in the following detaileddescription. Rather, the embodiments are chosen and described so thatothers skilled in the art may appreciate and understand the principlesand practices of the present application.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this application belongs. Although any method andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present application, the specific methodsand materials are now described.

Referring to FIG. 1A, an illustrative ankle spanning external fixationframe system 100 for fixating various bones or bone portions 80 inaccordance with the teachings of the present disclosure is illustratedin an environmental view. While this illustrative embodiment depicts theexternal fixation system 100 associated with a patient's lowerextremity, it should be understood and appreciated herein that theteachings of the present disclosure may similarly be utilized on anyskeletal portions of the human anatomy, including portions of the humananatomy beyond a patient's lower extremity. Moreover, while theillustrative embodiment depicted in FIG. 1A depicts an ankle spanningexternal fixation frame, it should be understood and appreciated hereinthat other lower extremity frame configurations can also be used inaccordance with the teachings of the present disclosure. Such otherlower extremity frames include, but are not limited to, a mid-shafttibia spanning frame (such as frame 101 shown in FIG. 1B) and a kneespanning frame (such as frame 103 shown in FIG. 1C).

Referring specifically to FIGS. 1A, 1B and 1C, the external fixationframe systems 100, 101 and 103 each include a proximal ring frame 102and a distal ring frame 104 positioned on opposite sides of afracture/fusion site of a patient's bones 80. The proximal and distalring frames 102, 104 are connected to each other by one or more frameconnectors or struts (e.g., ratcheting struts) 106, which can beselected from various sizes and configurations as needed. Illustrativeframe connecting struts 106 that may be used in accordance with theteachings of the present disclosure include, but are not limited to,those described in commonly assigned U.S. patent application Ser. No.13/464,502, which was filed on May 4, 2012, and published as U.S. PatentPublication No. 2013/0296857 on Nov. 7, 2013. The entire disclosure ofthis application is hereby incorporated in its entirety by thisreference.

Various clamps or clamping assemblies 108, which will be described inmore detail below, can be used with the frame connectors 106 orindependently of the frame connectors 106 for attaching bone pins orwires (e.g., transfixing pins, such as indicated by reference numeral110), and/or rods, bars, or other fixation devices (e.g., bone screws,such as indicated by reference numeral 112) as desirable for aparticular fixation procedure. While not necessarily required herein,the proximal and distal frames 102, 104, the frame connectors 106, theclamping assemblies 108, or any portions thereof, can beradiographically translucent such that the fixation system 100, 101 and103, when installed, can allow viewing of a fracture/fusion site of thebones 80 on X-ray film. The radiolucent components (or portions thereof)can be formed of, for example, carbon, composite, carbon fiber, or otherradiolucent materials.

As will be explained in detail below, various different kinds ofclamping assemblies 108 may be used with the external fixation systems100, 101 and 103 of the present teachings. The type, number, size andorder of the various clamping assemblies used to assemble the externalfixation frame will not only depend on what type of fixation procedureis being performed, but will also depend on the amount of rotational andtranslational degrees of freedom desired between the interconnectedcomponents. Some of the components that may be interconnected by theclamping assemblies of the present disclosure include, but are notnecessarily limited to, proximal and distal ring frames 102, 104, frameconnector struts 106, bone screws 112, pins 110, wires, rods, bars,shafts, and other such fixation devices.

Referring now to various clamping assemblies 108 that may be used inaccordance with the present disclosure, FIGS. 2A and 2B depict a firstillustrative clamping assembly 200 that includes a clamp body 202, alocking arm 204, a cam arm 206, a locking arm pivot pin 208 and a camarm pivot pin 210. During assembly of an external fixation frame system100, 101, 103, the clamping assembly 200 is configured to be snappedonto a ring frame 102, 104 or a rod by positioning the clamp body 202substantially perpendicular to the ring leg or rod and applying pressureto force end jaws 212 open and over the ring or rod (see FIGS. 4A, 4Band 4C, for instance, which illustrates an illustrative clampingassembly 201 attached to a ring frame 102). Alternatively, the clampingassembly 200 can be snapped onto the ring frame or rod by positioningthe clamp body 202 at the end of a ring leg or rod and applying pressureto slide the body onto the ring or rod.

Once positioned on the ring frame 102, 104 or rod, the locking arm 204is actuatable to compress and center the ring frame or rod inside theclamp body 202. To achieve this, the clamp may be provisionally lockedby rotating the locking arm 204 (via the locking arm pivot pin 208)towards and into a cam arm pocket 214. Once the surgeon is satisfiedwith the position and fixation of the bone fragments 80, the frame orfixator is definitively locked without the use of additional tools orequipment. To achieve the definitive lock, the cam arm 206 is rotatedtowards the clamp body 202 via the cam arm pivot pin 210 located at thecenter of the cam arm 206 until it approximates a top surface 213 of theclamp body 202.

Once the cam arm 206 is positioned against the clamp body 202 during adefinitive locking process, in accordance with certain aspects of thepresent disclosure, the cam arm 206 can be further locked into place byutilizing a locking pin that is configured to be inserted through thecam arm 206. More particularly, FIGS. 3A, 3B and 3C illustrate aclamping assembly 201 having a pair of upwardly projecting tabs 216extending from the clamp body 202 and each having a through-hole 217formed therein. When the cam arm 206 is positioned against the clampbody 202, the through-holes 217 align with a through-hole 219 formedinto the cam arm 206 such that a common through-hole is created. Thelocking pin (such as locking pin 144) can then be inserted through thiscommon through-hole, thereby preventing the cam arm 206 from beinglifted away from the clamp body 202 until the locking pin 144 is firstremoved.

By being able to provisionally lock any of the presently disclosedclamping assemblies, the surgeon is not only able to construct the frameor fixator on the patient as presented (i.e., the frame can adapt to thepatient's unique anatomy as opposed to requiring the patient's anatomyto first be adjusted in order to fit the frame), but the surgeon canperform the process without needing to utilize additional tools orequipment. As such, the surgeon will be able to position, align andstabilize the bone fragments with the assistance of a C-arm (X-ray) bydirectly manipulating the frame itself.

To position, align and stabilize the bone fragments once a clampingassembly (such as clamping assembly 200 or 201, for instance) isprovisionally locked to the fixation frame, in accordance with certainaspects of the present disclosure, a distraction handle assembly 114connected to the distal ring frame 104 can be utilized. In accordancewith this aspect of the present disclosure, and specifically referringto FIGS. 5A-5D, the distraction handle assembly 114 includes a pair ofdistraction handles 114A, 114B that can be manually gripped by thesurgeon to adjust the frame during the fracture reduction process asneeded. In other words, the surgeon grips the distraction handles 114A,114B and manipulates (e.g., pulls, pushes, twists) the handles asneeded, thereby causing the frame 100, 101 and 103 to respond and changeits orientation with respect to the patient's anatomy.

The pair of distraction handles 114A, 114B are connected by a cross barassembly 115, which provides a gripping feature for the distractionarms. In accordance with certain aspects of the present teachings, thedistraction handle assembly 114 may include a handle lock ring 117 thatis configured to lock the handle assembly 114 in an open position duringits operation. More particularly, in accordance with certain aspects ofthe present disclosure, the distraction handle assembly 114 is capableof being adjusted between two position—i.e., a first position (openstate) where the distraction handles 114A, 114B are at 90° to the crossbar 115 and a second position (closed state) where the handles arecollapsed against the cross bar. To rotate the arms from the open stateto the closed state, the user pulls up on each of the lock rings 117located around the handle pivot and rotates the handle assembly towardsthe cross bar.

In addition, and to ensure that the surgeon is able to safely adjust theexternal fixation assembly frames 100, 101 and 103 without exposing hisor her hands to the X-ray field during the adjustment process, thehandles 114A, 114B of the distraction handle assembly 114 are extendedfrom the distal ring frame 104 via a pair of distraction extension arms119 (see FIGS. 1A, 6A and 6B). According to certain aspects herein, eachextension arm 119 has a barrel 121 that provides a connection betweenthe cross bar assembly 115 and the distal ring frame 104. A fixedring/cross bar clamp 123 connects to the ring 104 or cross bar 115 in afixed position, while a pivoting ring/cross bar clamp 125 connects thering 104 or cross bar 115 in such a manner that it is rotatable 360°. Asthose of skill in the art will understand and appreciate herein, thebasic concept for the use of the distraction handle assembly 114 is toconnect the assembly to the pre-constructed external fixation frame(i.e., frames 100, 101 and 103) via the use of two distraction armextension assemblies 119. The distraction handle assembly is configuredto be used by a surgeon as an instrument to assist in the distractionand alignment of bone fractures which are “provisionally” stabilized bythe frame, as well as to protect or reduce the intensity of exposure toimaging radiation by allowing the surgeon to position his or her handsaway from the frame during a radiological event.

Unlike traditional external fixation systems that require surgeons tolock and unlock various portions of the frame in order to manuallyadjust and manipulate the orientation of the fixation frame with respectto a patient's anatomy, the external fixation frame systems 100, 101 and103 of the present disclosure are capable of being polyaxially adjusted(e.g., adjustment along several different axes) through a range ofmotion having a 360-degree pattern from a longitudinal axis (without theuse of additional tools or equipment) while the frame is provisionallylocked into place. To achieve such polyaxial adjustment, an adjustablepivot housing 120 is incorporated into the external fixation framesystem 100, 101 and 103 and is applied to the patient's bones prior toreducing the fracture. As used herein, the term “polyaxial” or“polyaxially” refers to the ability of a first element to pivot inmultiple planes with respect to a second element to which the firstelement is coupled. The adjustable locking polyaxial pivot housing 120can be used with either a bilateral frame system or a unilateral framesystem. When incorporated into the external fixation frame system, itallows the surgeon to provisionally position the bone fragments viaC-arm (X-ray) to align, stabilize and prevent additional neurovasculardamage without the need to definitively lock the frame by means ofadditional instruments or actions.

Various views of a polyaxial pivot housing in accordance with oneillustrative embodiment of the present disclosure is shown in FIGS.7A-7H. In accordance with this illustrative embodiment, the polyaxialpivot housing 120 includes a top ring 122, a bottom ring 124, asphere/post assembly 126 and a locking arm 128. The top ring 122 has aplatform 130 extending from its top surface 133 that is configured toconnect to a clamping assembly (clamping assembly 200 or 201, forexample) by threading the clamp into a threaded bore hole 132 of theplatform 130. When the housing 120 is assembled, the top ring 122provides a compressive loading along with the bottom ring 124 to therebyhold and center the sphere/post assembly's spherical body 129therebetween. As shown in FIG. 7G, to hold and center the spherical body129 in response to the compressive loading of the top ring 122, thebottom surface 137 of the top ring 122 includes a substantially circularrecessed cavity 127 that is dimensioned to accept the top portion of thespherical body 129 as the pivot housing 120 is locked relative to theframe. Similarly, as shown in FIG. 7H, the bottom ring 124 includes asubstantially circular cavity 131 that is dimensioned to accept thebottom portion of the spherical body 129 as the housing is locked intoplace.

The top ring 122 also includes three clearance holes 134 adapted toreceive locking bolts 136 that pass through the top ring 122 and threadinto the bottom ring 124 via three corresponding threaded holes 135.Because of the threaded relationship between the locking bolts 136 andthe bottom ring 124, when the frame 100, 101 and 103 is initiallyadjusted by the surgeon by pulling upon the distraction handle assembly114, the locking bolts 136 allow the polyaxial pivot housing 120 to beprovisionally locked into place in response to the compressive forcesand tension applied to the spherical body 129 by the top and bottomrings 122, 124 (i.e., it achieves a friction fit). Specifically, theprovisional lock is obtained when the top and bottom rings 122, 124 arepositioned so that the compressive force is applied to the sphericalbody 129 to prevent movement by soft-tissue forces. The friction fit andsoft tissue tension allows the surgeon to provisionally lock the frameand make minor adjustments to the bone alignment. Once the surgeon issatisfied with the fixation of the bone fragments, the frame can then bedefinitively locked to maintain the bone fragments within the desiredalignment.

To definitively lock the housing 120, in accordance with certainembodiments herein one of the locking bolts 136A is connected to thelocking arm 128 by way of a blind set screw 138 that passes through athreaded hole (not shown) of the locking arm 128 and presses against thelocking bolt 136A. As the locking cam arm 128 is rotated in a clockwisedirection, the set screw 138 prevents the locking bolt from movingindependent of the locking arm 128. As a result, as the locking arm 128is rotated about a longitudinal axis upon being pulled directionallytowards the spherical body 129, the bottom ring 124 is caused to movetowards the top ring 122, thereby compressing the spherical body 129between the top and bottom rings 122, 124. This clockwise rotation ofthe locking arm 128 causes the attached set screw 138 to also turn,thereby compressing the top and bottom rings 122, 124 further againstthe spherical body 129 to create a “locking fit” that prevents thesphere/post assembly 126 from moving with respect to the fixation frame100, 101 and 103.

As shown in FIGS. 7E and 8, in accordance with certain aspects of thepresent disclosure, the pivot housing 120 may further include a lockingpin 144 that is configured to hold the locking arm 128 in place once ithas been definitively locked. According to this embodiment, the top andbottom rings 122, 124, together with the locking arm 128, include aseries of aligned through-holes that are configured to receive thelocking pin 144 as it is inserted therethrough. Specifically, thelocking pin 144 is inserted into a through-hole 146A of the bottom ring124 from its outer surface, and particularly in such a manner that thelocking pin 144 continues to pass through the through-hole of thelocking arm 146 c and finally into the through-hole 146B of the top ring122. As shown in FIG. 8, the locking pin 144 includes a head portion 150on one end and a locking mechanism 152 on its opposite end. The headportion 150 is dimensioned in such a manner that it is unable to enterthe through-hole 146A of the bottom ring 124 as the locking pin isinserted therein. Since the head portion 150 has a circumferentialdimension larger than that of the through-hole 146A, when the lockingpin 124 is inserted therethrough, the head portion 150 is configured toserve as a stop surface as it flushingly engages the outer surface ofthe bottom ring 124. The locking mechanism 152 of the locking pin 124 isin turn configured to create a locking engagement with the through-hole146B of the top ring 122 when the locking pin 124 is fully insertedtherein. While various different locking arrangements may be utilized inaccordance with the present disclosure, in accordance with certainillustrative aspects herein, the locking mechanism 152 may be shaped insuch a manner that it creates a latching engagement with thethrough-hole. For instance, the locking pin 144 and/or its lockingmechanism 152 may be manufactured from a material that is compressibleor elastically deformable (e.g., plastic, rubber). In accordance withthis illustrative aspect, the locking mechanism 152 may include aslightly flared portion 157 that is configured to compress as it passesthrough the through-hole 146B, yet expand back to its originaldimensions after passing fully therethrough. To accomplish thisexpansion/retraction, a slot 159 may be formed into the lockingmechanism 152 that will allow the flared portion 157 to change itscircumferential dimensions by allowing it to move between an expandedand retracted position. Once returning to its original dimensions, thelocking mechanism 152 will expand to a size that is slightly larger thanthe dimensions of the through-hole 146B, thereby locking it into placerelative thereto.

Extending from the spherical body 129 is an attachment post 154 that isconfigured to attach the pivot housing 120 to a frame connector orratcheting strut 106 that bridges the proximal ring frame 102 to thedistal ring frame 104 (see FIGS. 9A and 9B, for instance). While theattachment post 154 and the spherical body 129 can be manufactured as asingle component or unit (e.g., overmolded into a single unit), inaccordance with certain aspects of the present disclosure, theattachment post 154 and the spherical body 129 may be independent of oneanother. For instance, the spherical body 129 may include a threadedaperture (not shown) that is configured to receive a threaded portion(not shown) of the attachment post 154.

As shown in FIGS. 10-14, another polyaxial pivot housing in accordancewith the teachings of the present disclosure is illustrated. Accordingto this embodiment, the polyaxial pivot housing 160 includes an outercollet housing 162, a compression collar or locking nut 164 and asphere/post assembly 166. The outer collet housing 162 has a platform170 extending from its top surface that is configured to connect to aclamping assembly (such as clamping assembly 201, for instance) bythreading the clamp into a threaded bore hole 172 of the platform 170.While the platform 170 may be integral with the outer collet housing 162such that the two are formed as a single unit, those of skill in the artwill understand and appreciate herein that the platform 170 can also bemanufactured as a separate piece that is in turn coupled to the housing(e.g., threaded, fused, welded, etc.).

In accordance with certain aspects of the present disclosure, thethreaded bore hole 172 is configured to house a spring mechanism 173(e.g., a coil spring), such that when the housing is assembled to anexternal fixation frame 100, 101, 103, the spring 173, together withsoft tissue tension, allows the surgeon to provisionally lock theexternal fixation frame and make minor adjustments to the bone alignmentas desired.

When the pivot housing 160 is assembled, the outer collet housing 162provides a compressive loading along with the locking nut 164 to therebyhold and center the spherical body 169 of the sphere/post assembly 166therebetween. To accomplish this, the outer collet housing 162 includesa series of threads 163 that are configured to threadingly mesh withcorresponding threads 165 of the locking nut 164. In accordance withcertain alternative aspects of the present disclosure, and asspecifically shown in FIG. 15, a pivot housing 161 may also include aseparate compression collet 167 that is configured to fit inside of aninner periphery 171 of the outer collet housing 162 such that when thethreads 175, 177 of the outer collect housing 162 and the locking nut164 are engaged, the compression collet 167 compresses around thespherical body 169 to provisionally or definitively lock the pivothousing 160 relative to the fixation frame 100, 101, 103. In accordancewith this aspect of the present disclosure, the outer collet housing 162is configured to prevent the compression collet 167 from rotating andguides the compression collet to compress against the spherical body 169during the locking process.

To provisionally lock the external fixation frame 100, 101, 103, thethreaded compression collar or locking nut 164 presses against the outercollet housing 162 (and/or compression collet 167 if optionally used) toprovide a friction fit. Specifically, the provisional lock is obtainedwhen the locking nut 164 and outer collet housing 162 (and/orcompression collet 167) are caused to provide a compressive force to thespherical body 169, thus preventing movement by soft-tissue forces. Thefriction fit and soft tissue tension allows the surgeon to provisionallylock the frame and make minor adjustments to the bone alignment. Oncethe surgeon is satisfied with the fixation of the bone fragments, theframe can then be definitively locked to maintain the bone fragmentswithin the desired alignment.

To definitively lock the pivot housing 160, the threads 165 of thelocking nut 164 are threadingly mated with the threads 163 of the outercollet housing 162, thereby compressing the sphere/post assembly 166therebetween (or by threadingly mating threads 175 and 177 if thecompression collet 167 is optionally used as shown with pivot housing161). A removable nut socket or wrench 176 can also be removablyattached to the outer periphery of the locking nut 164 and used tofurther tighten the threaded relationship between the outer collethousing 162 and the locking nut 164 if desired. To accomplish this, theouter periphery of the locking nut 164 may contain a series of ridges ornotches 178 that are configured to matingly correspond to a series ofridges or notches 180 on the inner periphery of the removable nut wrench176.

As those of skill in the art will understand herein, the removable nutwrench 176 can have an inner peripheral circumference that is slightlysmaller than that of the outer peripheral circumference of the lockingnut 164. In accordance with this embodiment, the removable nut wrench176 is defined by a partially cylindrical knob body 179 having one ormore hollowed out or concave portions or flutes 181 that are fabricatedinto its outer periphery to provide an improved gripping surface (i.e.,the surface can have an ergonomic contour that fits the user's handcomfortably). The knob body 179 is further defined by two end portionsor arms 183, 185 that are positioned substantially adjacent to oneanother, yet do not touch each other (i.e., they are separated by a gap187). As the nut wrench 176 is mated with the locking nut 164, the arms183, 185 are caused to separate (move away) from each other, therebyincreasing the size of the gap 187. While those of skill in the art willunderstand and appreciate herein that forming a gap or a voided regionwithin an otherwise solid object will impart some inherent elasticity tothe object, in accordance with certain aspects of the presentdisclosure, the body 179 may further be formed of a material havingelastic deformation properties to further enhance this quality asdesired. By causing the removable nut wrench 176 to be elasticallydeformable, as the wrench 176 is fitted over the locking nut 164, thewrench will return to its original shape once positioned over thelocking nut 164, thereby creating a snapping engagement thereto. Afterthe nut wrench 176 is used to further tighten the locking nut 164, itcan then be removed from the housing 160, 161 if desired so that thepatient (to which the external fixation frame is installed) is unable totamper with the frame.

Extending from the spherical body 169 is an attachment post 154 that isconfigured to connect (e.g., thread) the pivot housing 160, 161 to aframe connector or ratcheting strut 106 that bridges the proximal ringframe 102 to the distal ring frame 104. While the attachment post 154and the spherical body 169 can be manufactured as a single component orunit, in accordance with certain aspects of the present disclosure, theattachment post 154 and the spherical body 169 may be fabricatedindependently of one another. For instance, the spherical body 169 mayinclude a threaded aperture that is configured to receive a threadedportion of the attachment post 154. Moreover, the outer collet housing162 and the compression collet 167 (if used) each may be manufacturedfrom single pieces or multiple pieces interconnected if desired. Assuch, the present disclosure is not intended to be limited herein.

As shown in FIGS. 16A-16 D, another illustrative design for a polyaxialpivot housing 220 in accordance with another aspect of the presentdisclosure is shown. In accordance with this embodiment, the housing 220includes an outer sleeve 223 that is configured to receive a baseassembly 224 and a serrated sphere/post assembly 226, the serratedsphere/post assembly 226 being comprised of a spherical ball portion226A and a strut attachment post portion 226B. The base assembly 224 iscomposed of two separate base portions (i.e., a first base portion 224Aand a second base portion 224B) that are separated from each other by awave spring 228 (i.e., the first and second base portions 224A, 224Bsandwich the wave spring 228 therebetween). Specifically, the wavespring 228 is configured to be housed within a ridge or shelf 230 of thesecond base portion 224B. When the housing is assembled, the first andsecond base portions 224A, 224B mate with each other (via the wavespring 228) and force the serrated sphere/post assembly 226 into theouter sleeve 223. The spherical ball portion 226A of the serratedsphere/post assembly 226 in turn interfaces with a serrated baseassembly 231 that has an inner serrated periphery 232 that is configuredto matingly receive the outer surface of the spherical ball portion226A. When the housing 220 is assembled, anti-rotation screws 234 can beinserted into outer sleeve 223 to prevent the serrated base assembly 231from rotating inside of the outer sleeve 223.

A locking nut portion 236 is in turn configured to be threaded to theserrated base assembly 231 by way of a threaded post 238 that extendsfrom the serrated base assembly 231. In accordance with this aspect ofthe present disclosure, when the pivot housing 220 is assembled, theserrated base assembly 231 provides a compressive loading along with thelocking nut portion 236 to thereby hold and center the serratedspherical ball portion 226A of the sphere/post assembly 226therebetween. To accomplish this, the threaded post 238 includes aseries of threads 240 that are configured to threadingly mesh withcorresponding threads 241 within a bore hole 242 of the locking nutportion 236. A retaining ring 243 is held between the top surface of theserrated base assembly 231 and the bottom surface of the locking nutportion 236.

A clamping assembly platform 246 is in turn coupled to the locking nut'sbore hole 242 on the side opposite the threaded portion 241. Theclamping assembly platform 246 includes a threaded internal aperture(not shown) that is configured to receive a clamping assembly (such asassembly 108). To secure the clamping assembly platform 246 to thelocking nut portion 236, a retaining ring 248 is utilized.

As mentioned previously, once the external fixation frame is attached toa patient via percutaneous bone pins, the surgeon will position the bonefragments via C-arm (X-ray) to align, stabilize and prevent additionalneurovascular damage. The internal wave spring 228 and soft tissuetension experienced by the presently disclosed pivot housing 220 allowsthe surgeon to provisionally lock the frame and make minor adjustmentsto the bone alignment. Once the surgeon is satisfied with the fixationof the bone fragments, the frame may be definitively locked to maintainthe bone fragment's alignment. To achieve the definitive lock, thelocking nut portion 236 is rotated such that the internal thread movesthe serrated base assembly 231 against the serrated surface of theserrated spherical ball portion 226A of the sphere/post assembly 226.

The attachment post portion 226B that extends from the serratedspherical ball is configured to function as an means to connect (e.g.,thread) the pivot housing 220 to a frame connector or ratcheting strut106 that bridges the proximal ring frame 102 to the distal ring frame104.

As those of skill in the art will understand and appreciate herein,various different means can be utilized for provisionally anddefinitively locking any of the poly polyaxial pivot housings (e.g.,120, 160, 161 and 220) disclosed within of the present application. Forinstance, as shown in FIGS. 17A-17C, one or more self-locking retainingrings 250 can be mated with a top and/or bottom surfaces of thespherical ball portion 252 of the sphere/post assembly 254. Inaccordance with this illustrative aspect of the present disclosure, thespherical ball portion 252 is able to rotate freely inside the housing256 until an axial force drives the ball 252 into the socket. As thisforce is applied to the ball, the teeth 258 of the one or more retainingrings 250 are caused to dig into the ball, thereby preventing it fromfurther rotation. While the use of a retaining ring or rings may bedesirable to arrest movement of the ball 252 in accordance with certainaspects of the present disclosure, it should be understood andappreciated herein that in accordance with other embodiments, a seriesof teeth or ridges 260 can be fabricated into the inner periphery of thehousing 256 to arrest movement of the ball in lieu of (or in additionto) a retaining ring (see FIG. 17C). Despite the means chosen to arrestmovement of the ball 252 (e.g., retaining ring or fabricated ridges), toallow a threaded member (not shown) to apply additional compression tothe ball 252 and thereby achieve a permanent or definitive lock, aremovable wrench 262 can be connected to the compression collar 264 andtightened as explained above to compress the ball 252 within the housing256.

In accordance with yet another embodiment, and as is specifically shownin FIG. 18, a wave spring 270 can be inserted into the housing 272 suchthat it pinches the ball 274 on each side of its equator to achieve theprovisional lock. More particularly, as tension is applied to the framevia a strut, the ball 274 compresses the wave spring 270 so that thereis no longer contact with the edge of the socket. Permanent (definitive)fixation can be achieved by tightening the outer threads 276 of thehousing 278 until the ball 274 is tightly fixed.

As shown in FIGS. 19A and 19B, instead of pinching the ball 274 with awave spring, those of skill in the art will understand and appreciatethat it is also possible to include protrusions 280 from the ball thatare configured to matably engage corresponding recessed portions 282 ofthe socket 284 to prevent rotation. While not shown specifically herein,it is also possible to prevent rotation by including sharp spikes on thesocket that are designed to cut into a semi-soft ball.

In accordance with certain fixation procedures of the presentdisclosure, it may be desirable to position or stack one or moreclamping assemblies on top of each other. While it may be desirable toallow these stacked components to freely articulate with respect to oneanother in certain situations, in accordance with other aspects of thepresent teachings, it may be desirable to establish a fixed relationshipbetween these parts. While there are numerous ways to establish a fixedrelationship between any of the disclosed clamping assemblies discussedherein, in accordance with certain aspects of the present teachings, theclamping assemblies may have one or more serrated surfaces (see serratedsurface 222 of FIG. 3C, for instance) that are configured tostructurally mesh with one another when desired such that rotationalindependence of the stacked assemblies is not possible.

An illustrative embodiment of a stacked or combination rod/pin clampingassembly 300 in accordance with the present disclosure is shown withparticular reference to FIG. 20. The clamping assembly 300 in accordancewith this aspect of the present disclosure is operative for connectingvarious elongated members having a cylindrical shape, such as, forinstance rods and pins. The clamp assembly 300 is illustrated to includea first or lower clamp member 302 and a second or upper clamp member304. As used herein, terms of orientation, including but not limited tosuch as “upper” and “lower” are included merely for purposes ofreferencing the drawings and are not to be considered limiting innature. Explaining further, it will be readily apparent to those skilledin the art that any of the disclosed clamping assemblies (includingclamp assembly 300, for instance) are contemplated to be equallyoperative in any conceivable orientations with respect to one another,and as such, the various illustrative orientations shown within thedrawings are not intended to serve as an all-inclusive list of theavailable orientations to which these components can be used inconjunction with the presently disclosed external fixation framesystems.

The first clamp member 302 includes a pair of upper jaw portions 308 anda pair of lower jaw portions 310 which cooperate to define respectiveopenings 312 for receiving cylindrical rods and/or pins that are neededto assemble the external fixation system. Similarly, the second clampmember 304 includes a pair of upper jaw portions 314 and a pair of lowerjaw portions 316 which cooperate to define respective openings 318 forreceiving cylindrical rods and/or pins inserted therein as well.

In accordance with this illustrative embodiment, the first and secondclamp members 302, 304 are connected to one another by a threaded clampbolt 320 that passes through a common aperture 333 of the clamp membersin such a manner that it compresses the first and second clamp members302, 304 against one another, as well as the rods and/or pins heldtherein. The threaded clamp bolt 320 is configured to thread into a camlocking nut assembly 322 that is housed within an opening on the topsurface of the second clamp member 304. As shown in FIG. 21, the camlocking nut assembly 322 includes a body 327 that interfaces with thethreaded clamp bolt 320 to provide provisional locking, as well as apivot arm 334 which actuates the definitive lock with movement of a pairof offset cam rings 323. The offset cam rings 323 in turn transmitmotion of the pivot arm 334 around pivot posts 335 to a definitivelocking force against the first and second clamp members 302, 304 asthey are centered by the threaded clamp bolt 320. The offset cam rings323 and the cam lock pivot arm 334 are held on the pivot posts 335 andinto the cam locking nut body 327 by way of a pair of external lockingrings 329.

Once the various rods and/or pins are positioned within the first andsecond clamp members 302, 304, the clamps may be provisionally locked byturning (rotating) the cam locking nut assembly 322 around the threadedclamp bolt rod 320 until the assembly 300 is finger tight. As thethreaded clamp bolt 320 is tightened, an O-ring 324 acts as a spring,while an internal snap ring 326 holds the clamp bolt 320 and O-ring 324inside of the lower section of the first clamp member 302. Once thesurgeon is satisfied with the position and fixation of the bonefragments, the assembly 300 can be definitively locked by rotating thepivot arm 334 of the cam locking nut assembly 322 in a direction thatmoves the offset cam rings 323 into contact with the opposing items,thereby creating an additional offset distance and additional lockingload.

In accordance with certain aspects of the present teachings, the firstand second clamp members 302, 304 may have a series of axial slots 328formed into their respective bodies. According to certain aspects ofthis embodiment, the axial slots may be positioned adjacent to and/or atleast partially terminating into the openings 312, 318 to thereby allowthe jaw portions of the clamp members to be elastically displaced inresponse to a cylindrical rod, pin or the like being introduced therein.In other words, as a rod, pin, etc. is laterally introduced into one ofthe openings 312, 318, the upper and lower jaw portions of that clampingmember are urged apart from one another. Once the cylindrical object isfully seated within the upper and lower jaw portions of the clampingmember, a counter-force snappingly retains the object temporarily inplace, particularly as the upper and lower jaw portions return to theiroriginal position prior to being displaced. As those of skill in the artwill understand and appreciate herein, by fabricating such axial slots328 into the clamping assembly, the elastic deformation propertiesassociated with such a design inherently allows the upper and lower jawportions to function much like a leaf spring, and as a result,cylindrical items placed therein can be snappingly retained within thedefined opening.

To provide means for arresting rotational movement of the first clampmember 302 relative to the second clamp member 304 about a longitudinalaxis of the clamp bolt 320, the first and second clamp members 302 and304 may be formed to include cooperating serrations. As shown byreference numeral 222 in FIG. 3C for instance, an upper surface of thefirst clamp member 302 can similarly include a serrated portion having aplurality of serrations radially extending from a common aperture. Theserrated portion can be adapted to engage a substantially identicalserrated portion provided on an adjacent lower surface of the secondclamp member 304. When the clamp bolt 320 compresses the first andsecond clamp member 302, 304 against each other as the cam locking nutassembly 322 is initially tightened, the serrated portions of the firstand second clamp members 302 and 304 are drawn together to preventrelative movement therebetween.

Moving now to FIG. 22, a universal ring frame to rod/pin clamp assembly400 in accordance with another teaching of the present disclosure isdepicted. The clamp assembly 400 is illustrated to include a first orlower clamp member 402 and a second or upper clamp member 404. The firstclamp member 402 includes a clamp body 406, a locking arm 408, a cam arm410, a locking arm pivot pin 412 and a cam arm pivot pin 414. The firstclamp member 402 is configured to be snapped onto a ring frame 102, 104or a rod by positioning the clamp body 406 substantially perpendicularto the ring leg or rod and applying pressure to force end jaws 416 openand over the ring or rod. Alternatively, the first clamp member 402 canbe snapped onto the ring frame or rod by positioning the clamp body 406at the end of a ring leg or rod and applying pressure to slide the bodyonto the ring or rod.

The second clamp member 404 includes a pair of upper jaw portions 418and a pair of lower jaw portions 420 which cooperate to define openings421 for receiving cylindrical rods and/or pins that are needed toassemble the external fixation system.

In accordance with this illustrative embodiment, the first and secondclamp members 402, 404 are connected to one another by a threaded clampbolt 422 that passes through a common aperture 424 of the clamp membersin such a manner that it compresses the first and second clamp members402, 404 against one another, as well as the rings, rods and/or pinsheld therein. The threaded clamp bolt 422 is configured to thread into acam locking nut assembly 436. As shown in FIG. 23, the cam locking nutassembly 436 includes a body 437 that interfaces with the threaded clampbolt 422 to provide provisional locking, as well as an off-set cam pivotarm 438 which pivots around a pair of low profile or bottom head capscrews 439.

Once the various rods, pins and/or rings are positioned within the firstand second clamp members 402, 404, the clamps may be provisionallylocked by turning the cam locking nut assembly 436 around the threadedclamp bolt rod 422 until the assembly 400 is finger tight. As thethreaded clamp bolt 422 is tightened, an O-ring 428 acts as a spring,while an internal snap ring 430 holds the clamp bolt 422 and O-ring 428inside of the lower section of the first clamp member 402. Moreover, thelocking arm 408 of the first clamp member 402 is rotated (via thelocking arm pivot pin 412) towards and into a cam arm pocket 415 tofurther create a provisional lock with respect to the first clampmember.

Once the surgeon is satisfied with the position and fixation of the bonefragments, the assembly can be definitively locked by rotating the pivotarm 438 of the cam locking nut assembly 436 to create an additionaloffset distance and additional locking load, as well as by rotating thecam arm 410 of the first clamp member 402 towards the clamp body 406 viathe cam arm pivot pin 414 located at the center of the cam arm 410 untilit touches the clamp body 406.

In accordance with certain aspects of the present teachings, the secondclamp member 404 may have a series of axial slots 434 formed into itsbody. According to certain aspects of this embodiment, the axial slotsmay be positioned adjacent to and/or at least partially terminating intothe openings 421 to thereby allow the jaw portions 418, 420 to beelastically displaced in response to a cylindrical rod, pin or the likebeing introduced therein. In other words, as a rod, pin, etc. islaterally introduced into one of the openings 421, the upper and lowerjaw portions defining that opening are urged apart from one another.Once the cylindrical object is fully seated within the upper and lowerjaw portions, a counter-force snappingly retains the object temporarilyin place, particularly as the upper and lower jaw portions return totheir original position prior to being displaced. As those of skill inthe art will understand and appreciate herein, by fabricating such axialslots 434 into the clamp member, the elastic deformation propertiesassociated with such a design inherently allows the upper and lower jawportions to function much like a leaf spring, and as a result,cylindrical items placed therein can be snappingly retained within thedefined opening.

To provide means for arresting rotational movement of the first clampmember 402 relative to the second clamp member 404 about a longitudinalaxis of the clamp bolt 422, the first and second clamp members 402 and404 may be formed to include cooperating serrations as described abovewith respect to assembly 201.

Referring to FIG. 24, a universal ring-to-post clamp assembly 500 isprovided. In accordance with this embodiment, the assembly 500 comprisesa post body 502 that interfaces with the ring clamp body 504. Moreparticularly, the clamping assembly 500 includes a clamp body 504, alocking arm 506, a cam arm 508, a locking arm pivot pin 510, a cam armpivot pin 512, and a post body 502 that interfaces with the clamp body504.

In accordance with this illustrative embodiment, the universal post body502 and the ring clamp body 504 are connected to one another by athreaded clamp bolt 522 that passes through a common aperture 523 of thebodies 502, 504 in such a manner that it compresses the bodies againstone another, as well as the ring held therein. The threaded clamp bolt522 is configured to thread into a cam locking nut assembly 436 that ishoused within an opening on the top surface of the universal post body502.

Once the ring frame is positioned within the ring clamp body 504, theclamp may be provisionally locked by turning the cam locking nutassembly 436 around the threaded clamp bolt rod 522 until the assembly500 is finger tight. As the threaded clamp bolt 522 is tightened, anO-ring 528 acts as a spring, while an internal snap ring 530 holds theclamp bolt 522 and O-ring 528 inside of the lower section of the clampbody 504. Moreover, the locking arm 506 of the ring clamp body 502 isrotated (via the locking arm pivot pin 510) towards and into a cam armpocket 515 to further create a provisional lock with respect to thefirst clamp member.

Once the surgeon is satisfied with the position and fixation of the bonefragments, the assembly can be definitively locked by rotating the pivotarm 438 of the cam locking nut assembly 436 to create an additionaloffset distance and locking load, as well as by rotating the cam arm 508towards the ring clamp body 502 via the cam arm pivot pin 512 located atthe center of the cam arm 508 until it touches the clamp body 502.

To provide means for arresting rotational movement of the first andsecond bodies, 502, 504 relative to one another about a longitudinalaxis of the clamp bolt 522, the first and second bodies 502, 504 may beformed to include cooperating serrations as described above with respectto assembly 201.

Referring to FIG. 25, another illustrative clamping assembly 600 inaccordance with the present disclosure is illustrated. This illustrativeassembly is similar to clamping assembly 300 illustrated in FIG. 20 yetincludes two cam locking nut assemblies in conjunction with acentralized serrated washer component. In accordance with this aspect ofthe present disclosure, the clamping assembly 600 is operative forconnecting various elongated members having a cylindrical shape, suchas, for instance rods and pins. The clamp assembly 600 is illustrated toinclude a first or lower clamp member 602 and a second or upper clampmember 604. The first clamp member 602 includes a pair of upper jawportions 608 and a pair of lower jaw portions 610 which cooperate todefine respective openings 612 for receiving cylindrical rods and/orpins that are needed to assemble the external fixation system.Similarly, the second clamp member 604 includes a pair of upper jawportions 614 and a pair of lower jaw portions 616 which cooperate todefine respective openings 618 for receiving cylindrical rods and/orpins inserted therein as well.

In accordance with this illustrative embodiment, the first and secondclamp members 602, 604 are spaced apart or separated from one another bya serrated washer assembly 621 that holds and contains first and secondthreaded clamp bolts 622A, 622B that are each configured toindependently pass through an aperture formed within one of therespective clamp members 602, 604. In particular, the serrated washerassembly 621 has a first serrated surface 625A and an opposing secondserrated surface 625B, the first and second serrated surfaces beingsubstantially parallel to one another. The first and second serratedsurfaces 625A, 625B each include a substantially circular recessedportion or cavity (not particularly shown) that is configured to receivean O-ring 633A, 633B associated with the respective first and secondthreaded clamp bolts 622A, 622B. The O-rings 633A, 633B are in turncompressed against the threaded clamp bolts 622A, 622B by washers 628A,628B.

The first and second threaded clamp bolts 622A, 622B are each configuredto thread into a cam locking nut assembly 436 that is respectivelyhoused within an opening of the first and second clamp members 602, 604.As shown in FIG. 23, the cam locking nut assemblies 436 include a body437 that interfaces with the threaded clamp bolts 622A, 622B to provideprovisional locking, as well as a locking pivot arm 438 which pivotsaround a low profile or button head cap screws 439 and has an off-setcam that adds distance for tightening the threaded clamp bolts 622A,622B.

Once the various rods and/or pins are positioned within the first andsecond clamp members 602, 604, the clamps may be provisionally locked byturning the respective cam locking nut assemblies 436 around thethreaded clamp bolts 622A, 622B until the assembly 600 is finger tight.As the threaded clamp bolts 622A, 622B are tightened, the O-rings 633A,633B act as springs, while internal snap rings 640 a, 640 b hold theclamp bolts 622A, 622B, O-rings 633A, 633B and washers 628 a, 628 binside of the serrated washer assembly 621. Once the surgeon issatisfied with the position and fixation of the bone fragments, theassembly 600 can be definitively locked by rotating the locking pivotarms 638 of the cam locking nut assemblies 436 in a direction that movesthe offset cam rings into contact with the opposing item, therebycreating an additional offset distance and additional locking load.

In accordance with certain aspects of the present teachings, the firstand second clamp members 602, 604 may have a series of axial slots 642formed into their respective bodies. According to certain aspects ofthis embodiment, the axial slots may be positioned adjacent to and/or atleast partially terminating into the openings 612, 618 to thereby allowthe jaw portions of the clamp members to be elastically displaced inresponse to a cylindrical rod, pin or the like being introduced therein.In other words, as a rod, pin, etc. is laterally introduced into one ofthe openings 612, 618, the upper and lower jaw portions of that clampingmember are urged apart from one another. Once the cylindrical object isfully seated within the upper and lower jaw portions of the clampingmember, a counter-force snappingly retains the object temporarily inplace, particularly as the upper and lower jaw portions return to theiroriginal position prior to being displaced. As those of skill in the artwill understand and appreciate herein, by fabricating such axial slots642 into the clamping assembly, the elastic deformation propertiesassociated with such a design inherently allows the upper and lower jawportions to function much like a leaf spring, and as a result,cylindrical items placed therein can be snappingly retained within thedefined opening.

To provide means for arresting rotational movement of the first clampmember 602 relative to the second clamp member 604 about a longitudinalaxis of the clamp bolts 622A, 622B, the first and second clamp members602 and 604 may be formed to include cooperating serrated portions orsurfaces that are configured to interact with the serrated surfaces625A, 625B of the serrated washer assembly 621. The serrated portions ofthe first and second clamp members 602, 604 can be adapted to engage theserrated surfaces 625A, 625B of the serrated washer assembly 621 suchthat when the clamp bolts 622A, 622B compress the first and second clampmember 602, 604 against the serrated washer assembly 621 as the camlocking nut assemblies 636A, 636B are initially tightened, the serratedportions of the first and second clamp members 602 and 604 are drawnagainst the serrated surfaces 625A, 625B of the washer assembly suchthat relative movement between the first and second clamp members isprevented.

Referring to FIG. 26, an illustrative universal rod/pin clampingassembly 700 in accordance with the present disclosure is illustrated.The clamping assembly 700 is illustrated to include a first or lowerclamp member 702 and a second or upper clamp member 704. The first clampmember 702 includes a pair of upper jaw portions 708 and a pair of lowerjaw portions 710 which cooperate to define respective openings 712 forreceiving cylindrical rods and/or pins that are needed to assemble theexternal fixation system. Similarly, the second clamp member 704includes a pair of upper jaw portions 714 and a pair of lower jawportions 716 which cooperate to define respective openings 718 forreceiving cylindrical rods and/or pins inserted therein as well.

In accordance with this illustrative embodiment, the first and secondclamp members 702, 704 are coupled to one another by a pair of lockingassemblies 721A, 721B that are each independently configured to pivotwith respect to one another, as well as with respect to the clampmembers 702, 704. In accordance with this aspect of the presentdisclosure, the bottom surface of a second pivot body 719B of the secondlocking assembly 721B is configured to rest upon the top surface of afirst pivot body 719A of the first locking assembly 721A. Both the firstand second pivot bodies 719A, 719B each have a through-hole (not shown)such that when they are stacked on top of each other, a commonthrough-hole is created. Within this common through-hole is housed auniversal serrated washer 725. The universal serrated washer 725 has apair of opposing serrated surfaces 725A (only one surface shown), aswell as a pair of retaining ring grooves (not shown). When assembled, apair of retaining rings 723A, 723B is inserted within the grooves andserve as a means for preventing the first and second pivot bodies 719A,719B from disengaging from one another.

The first and second clamp members 702, 704 are coupled to first andsecond threaded clamp bolts 724A, 724B that are each configured toindependently pass through apertures which are formed in the respectiveclamp members 702, 704. The first and second threaded clamp bolts 724A,724B are each configured to thread into a threaded aperture (not shown)of the serrated washer 725.

Once the various rods and/or pins are positioned within the first andsecond clamp members 702, 704, the clamps may be provisionally andindependently locked by rotating their respective locking pivot arm738A, 738B (via the locking arm pivot pins 740A, 740B) towards and intocam arm pockets. Once the surgeon is satisfied with the position andfixation of the bone fragments, the frame or fixator can be definitivelylocked without the use of additional tools or equipment. To achieve thedefinitive lock, the cam arms 739A, 739B are rotated towards the clampmembers 702, 704 via the cam arm pivot pins 741A, 741B located at thecenter of the respective cam arms 739A, 739B until it touches the clampmember.

Once the cam arms 739A, 739B are positioned within the clamp members702, 704 during a definitive locking process, in accordance with certainaspects of the present disclosure, the cam arms 739A, 739B can befurther locked into place by utilizing a locking pin (not shown) that isconfigured to be inserted through apertures 743A, 743B of the cam arms739A, 739B. According to this embodiment, the clamp members 702, 704each have a pair of upwardly projecting tabs 742A, 742B, each having athrough-hole formed therein. When the cam arms 739A, 739B are positionedwithin the clamp members 702, 704, the through-holes align withapertures 743A, 743B formed into the cam arms 739A, 739B such that acommon through-hole is created. The locking pin can then be insertedthrough this common through-hole, thereby preventing the cam arms 739A,739B from being individually lifted away from the clamp members 702, 704until the locking pin is first removed.

To provide means for arresting rotational movement of the first clampmember 702 relative to the second clamp member 704 about a longitudinalaxis of the clamp bolts 724A, 724B, the first and second clamp members702 and 704 may be formed to include cooperating serrated portions orsurfaces that are configured to interact with serrated surface 725A ofthe serrated washer assembly 725. The serrated portions of the first andsecond clamp members 702, 704 can be adapted to engage the serratedsurfaces of the serrated washer 725 such that when the clamp bolts 724A,724B compress the first and second clamp member 702, 704, the serratedportions of the first and second clamp members 702 and 704 are drawnagainst the serrated surface of the serrated washer 725 such thatrelative movement between the first and second clamp members isprevented.

In accordance with certain aspects of the present teachings, the firstand second clamp members 702, 704 may have a series of axial slots 746formed into their respective bodies. According to certain aspects ofthis embodiment, the axial slots may be positioned adjacent to and/or atleast partially terminating into the openings 712, 718 to thereby allowthe jaw portions of the clamp members to be elastically displaced inresponse to a cylindrical rod, pin or the like being introduced therein.In other words, as a rod, pin, etc. is laterally introduced into one ofthe openings 712, 718, the upper and lower jaw portions of that clampingmember are urged apart from one another. Once the cylindrical object isfully seated within the upper and lower jaw portions of the clampingmember, a counter-force snappingly retains the object temporarily inplace, particularly as the upper and lower jaw portions return to theiroriginal position prior to being displaced. As those of skill in the artwill understand and appreciate herein, by fabricating such axial slots746 into the clamping assembly, the elastic deformation propertiesassociated with such a design inherently allows the upper and lower jawportions to function much like a leaf spring, and as a result,cylindrical items placed therein can be snappingly retained within thedefined opening.

Referring to FIGS. 27 and 28, another illustrative clamping assembly 800in accordance with the present disclosure is illustrated. In accordancewith this aspect of the present disclosure, the illustrative clampingassembly 800 is a universal ring frame to rod/pin clamp assembly.According to this aspect of the present disclosure, the clamp assembly800 is illustrated to include a first or lower clamp member 802 and asecond or upper clamp member 804. The first clamp member 802 includes aclamp body 806, a locking arm 808, a cam arm 810, a locking arm pivotpin 812 and a cam arm pivot pin 814. The first clamp member 802 isconfigured to be snapped onto a ring frame or a rod (e.g., ring frames102, 104) by positioning the clamp body 806 substantially perpendicularto the ring leg or rod and applying pressure to force end jaws 816 openand over the ring or rod. Alternatively, the first clamp member 802 canbe snapped onto the ring frame or rod by positioning the clamp body 806at the end of a ring leg or rod and applying pressure to slide the bodyonto the ring or rod.

The second clamp member 804 includes a pair of upper jaw portions 818and a pair of lower jaw portions 820 which cooperate to define openings821 for receiving cylindrical rods and/or pins that are needed toassemble the external fixation system.

In accordance with this illustrative embodiment, the first and secondclamp members 802, 804 are connected to one another by a threaded clampbolt 822 that passes through a common aperture of the clamp members insuch a manner that it compresses the first and second clamp members 802,804 against one another, as well as the rings, rods and/or pins heldtherein.

Once the various rings, rods and/or pins are positioned within the firstand second clamp members 802, 804, first and second locking assembliescompress and hold the rings, rods and/or pins therein. To achieve this,the clamp members may be provisionally and independently locked. Toprovisionally lock the first clamp member 802, the locking arm 808 isrotated (via the locking arm pivot pin 812) towards and into a cam armpocket 813. Once the surgeon is satisfied with the position and fixationof the bone fragments, the frame or fixator can be definitively lockedwithout the use of additional tools or equipment. To achieve thedefinitive lock, the cam arm 810 is rotated towards the clamp body 806via the cam arm pivot pin 814 located at the center of the cam arm 810until it touches the clamp body.

Similarly, to independently and provisionally lock the second clampmember 804, a locking arm 830 that is coupled to the second clamp memberis rotated (via the locking arm pivot pin 832) towards and into a camarm pocket 833. Once the surgeon is satisfied with the position andfixation of the bone fragments, the frame or fixator can be definitivelylocked without the use of additional tools or equipment. To achieve thedefinitive lock, the cam arm 834 is rotated towards the second clampmember 804 via a cam arm pivot pin 836 located at the center of the camarm 834 until it touches the second clamp member.

Once the cam arms 810, 834 are positioned within their respective clampmembers 802, 804 during a definitive locking process, in accordance withcertain aspects of the present disclosure, the cam arms 810, 834 can befurther locked into place by utilizing a locking pin (not shown) that isconfigured to be inserted through the cam arms 810, 834. According tothis embodiment, the clamp members 802, 804 each have a pair of upwardlyprojecting tabs 842A, 842B with through-holes formed therein. When thecam arms 810, 834 are positioned within the clamp members 802, 804, thethrough-holes align with a through-hole formed into the cam arms 810,834 such that a common through-hole is created. The locking pin can thenbe inserted through this common through-hole, thereby preventing the camarms 810, 834 from being individually lifted away from the clamp members802, 804 until the locking pin is first removed.

While clamping assembly 800 can be configured such that the first andsecond clamp members 802, 804 are able to independently rotate withrespect to one another, in accordance with certain aspects of thepresent disclosure, it may be desirable to arrest angular or rotationalmovement between such components. To provide means for arresting suchmovement of the first clamp member 802 relative to the second clampmember 804 about an a longitudinal axis of the clamp bolt 822, the firstand second clamp members 802 and 804 may be formed to includecooperating serrated portions or surfaces that are configured tointeract with each other such that relative movement between the firstand second clamp members is prevented.

In accordance with certain aspects of the present teachings, the secondclamp member 804 may have a series of axial slots 846 formed into itsbody. According to certain aspects of this embodiment, the axial slotsmay be positioned adjacent to and/or at least partially terminating intothe openings 821 to thereby allow the jaw portions of the clamp memberto be elastically displaced in response to a cylindrical rod, pin or thelike being introduced therein. In other words, as a rod, pin, etc. islaterally introduced into one of the openings 821, the upper and lowerjaw portions of that clamping member are urged apart from one another.Once the cylindrical object is fully seated within the upper and lowerjaw portions of the clamping member, a counter-force snappingly retainsthe object temporarily in place, particularly as the upper and lower jawportions return to their original position prior to being displaced. Asthose of skill in the art will understand and appreciate herein, byfabricating such axial slots 846 into the clamping assembly, the elasticdeformation properties associated with such a design inherently allowsthe upper and lower jaw portions to function much like a leaf spring,and as a result, cylindrical items placed therein can be snappinglyretained within the defined opening.

FIG. 29 depicts an illustrative universal ring-to-post clamping assembly900 in accordance with one embodiment of the present teachings. Inaccordance with this aspect of the present disclosure, the clampingassembly 900 includes a clamp body 902, a locking arm 904, a cam arm906, a locking arm pivot pin 908, a cam arm pivot pin 910, a universalpost 912 (which is configured to interface with a universal rod/pinclamp assembly) and a retaining pin 914 that retains the universal postinto the clamp body 902.

Once the clamp body 902 is positioned on a ring frame, the locking arm904 compresses and centers the ring frame inside the clamp body 902. Toachieve this, the clamp may be provisionally locked by rotating thelocking arm 904 (via the locking arm pivot pin 908) towards and into acam arm pocket 916. Once the surgeon is satisfied with the position andfixation of the bone fragments, the frame or fixator is definitivelylocked without the use of additional tools or equipment. To achieve thedefinitive lock, the cam arm 906 is rotated towards the clamp body 902via the cam arm pivot pin 910 located at the center of the cam arm 906until it touches the clamp body 902.

Once the cam arm 906 is positioned against the clamp body 902 during adefinitive locking process, in accordance with certain aspects of thepresent disclosure, the cam arm 906 can be further locked into place byutilizing a locking pin (not shown) that is configured to be insertedthrough the cam arm 906. According to this embodiment, the clamp body902 has a pair of upwardly projecting tabs 918, each having athrough-hole formed therein. When the cam arm 906 is positioned againstthe clamp body 902, the through-holes align with a through-hole formedinto the cam arm 906 such that a common through-hole is created. Thelocking pin can then be inserted through this common through-hole,thereby preventing the cam arm 906 from being lifted away from the clampbody 902 until the locking pin is first removed.

While an exemplary embodiment incorporating the principles of thepresent application has been disclosed hereinabove, the presentapplication is not limited to the disclosed embodiments. Instead, thisapplication is intended to cover any variations, uses, or adaptations ofthe application using its general principles. Further, this applicationis intended to cover such departures from the present disclosure as comewithin known or customary practice in the art to which this presentapplication pertains and which fall within the limits of the appendedclaims.

The terminology used herein is for the purpose of describing particularillustrative embodiments only and is not intended to be limiting. Asused herein, the singular forms “a”, “an” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on”, “engaged to”,“connected to” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto”, “directly connected to” or “directly coupled to” another element orlayer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”,“lower”, “above”, “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations).

The invention claimed is:
 1. A polyaxial pivot housing for an externalfixation system comprising: a first plate; a second plate substantiallyparallel to the first plate; a spherical member positioned between thefirst and second plates, the spherical member having a threaded postthat is configured to attach to a support member of an external fixationframe; and a pivotably rotatable locking arm, the locking arm beingconfigured to rotate about a longitudinal axis of the spherical memberupon being pulled directionally toward the spherical member in order toorientationally lock the threaded post with respect to the externalfixation frame by compressing the first and second plates against thespherical member.
 2. The polyaxial pivot housing of claim 1, wherein thefirst plate includes a threaded bore hole configured to attach to anexternal fixation clamping assembly.
 3. The polyaxial pivot housing ofclaim 1, wherein the first and second plates are connected by a lockingbolt.
 4. The polyaxial pivot housing of claim 1, further including alocking pin that is configured to prevent movement of the locking arm.5. The polyaxial pivot housing of claim 1, wherein the first plateincludes a first substantially circular recessed cavity that isdimensioned to receive a top portion of the spherical member.
 6. Thepolyaxial pivot housing of claim 5, wherein the second plate includes asecond substantially circular recessed cavity that is dimensioned toaccept a bottom portion of the spherical member.
 7. The polyaxial pivothousing of claim 1, wherein the housing includes a provisional lockingfeature that allows the alignment of bone fragments held by the externalfixation frame to be slightly adjusted by overcoming a friction fit thatis caused by compressive forces and soft tissue tension, the provisionallocking feature being actuatable without the use of a tool.
 8. Thepolyaxial pivot housing of claim 1, wherein the housing includes adefinitive locking feature that allows bone fragments held by theexternal fixation frame to be secured in a defined alignmentorientation, the definitive locking feature being manually actuatablewithout the use of a tool.
 9. The polyaxial pivot housing of claim 8,wherein the definitive locking feature is actuated by moving thepivotably rotatable locking arm towards the spherical member about thelongitudinal axis, the movement causing the second plate to compress thespherical member against the first plate.
 10. The polyaxial pivothousing of claim 9, further comprising a set screw associated with thepivotably rotatable locking arm, the set screw being configured toprevent a locking bolt that passes through the first and second platesfrom moving independently of the pivotably rotatable locking am as thelocking arm is moved about the longitudinal axis.
 11. A polyaxial pivothousing for an external fixation system, comprising: a first plate; asecond plate substantially parallel to the first plate; a locking screwconnecting the first and second plates; a spherical member positionedbetween the first and second plates, the spherical member having athreaded post that is configured to attach to a support member of anexternal fixation frame; and a pivotably rotatable locking arm, thelocking arm being configured to rotate about a longitudinal axis of thespherical member upon being pulled directionally toward the sphericalmember in order to orientationally lock the threaded post with respectto the external fixation frame by compressing the first and secondplates against the spherical member; wherein the polyaxial pivot housinghas a provisional locking feature and a definitive locking feature, eachlocking feature being manually actuatable without the use of a tool. 12.The polyaxial pivot housing of claim 11, wherein the first plateincludes a threaded bore hole configured to attach to an externalfixation clamping assembly.
 13. The polyaxial pivot housing of claim 11,further including a locking pin that is configured to prevent movementof the locking arm.
 14. The polyaxial pivot housing of claim 11, whereinthe first plate includes a first substantially circular recessed cavitythat is dimensioned to receive a top portion of the spherical member.15. The polyaxial pivot housing of claim 14, wherein the second plateincludes a second substantially circular recessed cavity that isdimensioned to accept a bottom portion of the spherical member.
 16. Thepolyaxial pivot housing of claim 11, wherein the provisional lockingfeature is configured to allow the alignment of bone fragments held bythe external fixation frame to be slightly adjusted by overcoming afriction fit that is caused by compressive forces and soft tissuetension.
 17. The polyaxial pivot housing of claim 11, wherein thedefinitive locking feature is configured to allow bone fragments held bythe external fixation frame to be secured in a defined alignmentorientation.
 18. The polyaxial pivot housing of claim 17, wherein thedefinitive locking feature is actuated by moving the pivotably rotatablelocking arm towards the spherical member about the longitudinal axis,the movement causing the second plate to compress the spherical memberagainst the first plate.
 19. The polyaxial pivot housing of claim 18,further comprising a set screw associated with the pivotably rotatablelocking arm, the set screw being configured to prevent a locking boltthat passes through the first and second plates from movingindependently of the pivotably rotatable locking am as the locking armis moved about the longitudinal axis.